With the rapid development of the display technology, touch panels have been widely used in people's lives. Currently, depending on the structure, the touch panels may be classified into add on mode touch panels, on cell touch panels and in cell touch panels. For the add on mode touch panel, the touch panel and a liquid crystal display (LCD) panel are produced separately, and then attached together so as to form the LCD panel having a touch function. However, there exist some drawbacks in the add on mode touch panel, such as high manufacturing cost, low light transmittance and a thick module. For the in cell touch panel, a touch electrode of the touch panel is built inside the LCD panel so as to reduce the overall thickness of the module and remarkably reduce its manufacturing costs. Thus the in cell touch panel is favored by the major manufacturers.
At present, the existing in cell touch screens primarily detect the touch position of a finger according to the principle of the self-capacitance. In implementation, the thin film transistor (TFT) array substrate is provided with additional touch electrodes. Due to the above-mentioned structure design of the in cell touch panel, it is necessary to add a new film layer (the transparent conductive layer serving as a touch electrode) on the existing TFT array substrate, so that a new process needs to be added during manufacturing of the TFT array substrate and the production costs are increased, it does not facilitate improvement of the production efficiency.